Modern radiological scanning systems are capable of providing detailed imaging of a patient's body in the nature of a cross-sectional view. That is, these systems can provide a “thin slice” image of various organs and portions of the body taken at different orientations including different elevations and from different points of view. These images require annotation of orientation, including sidedness, for left versus right orientation. Typical systems involve a patient being introduced into a scanning system on a sliding horizontal platform, either head first or feet first. Presently the system operator will key in the orientation of the patient on the platform and the resulting images will bear an indication of this orientation. Often major surgery is performed based upon these scan images and the orientation indication is critical to performing the surgery on the correct side of the patient. As the orientation input is under the control of the system operator, errors are possible. If the operator enters “feet first” instead of “head first” the image will be marked incorrectly by the machine. Similar problems can occur when an operator enters “prone” versus “supine.”
For example, due to symmetry of anatomy, it is not possible to examine a brain sectional image and determine which side is the left side of the brain and which is the right. An error here could result in surgery on the wrong side of a patient's head. Even for body areas with inherent asymmetry, for example the chest and abdomen, any person born with situs inversus, this anatomy is reversed, leading to confusion and possible errors. To-date, no foolproof system has been developed to determine the orientation used in producing these scanned images. Similarly, with standard X-ray a technician can mislabel left versus right when he manually places a marker on the film cassette.
Various systems have been developed to identify the orientation used in scanning systems. U.S. Pat. No. 6,678,353, issued to Graumann et al., discloses a method applied and an x-ray system for determining a spatial relationship of X-ray datasets measured independently of one another, an x-ray apparatus registers X-ray datasets of a patient and a scale is provided that makes position data available that are identifiable in at least one of the registered dataset. The position data serve for the determination of the spatial relationship between at least two X-ray datasets that were registered from different body portions of the patient.
U.S. Pat. No. 4,583,538, issued to Onik et al. is directed to a method and apparatus which allow for CT guided biopsies of the body. The method is based on the finding of a reference point on the patient's body that exactly correlates to a point on the CT scan. This is accomplished by means of a localization device placed on the patient's skin which can be identified in cross section on the CT scan. Measurements of the localization device on CT scan can then be correlated to the device on the patient.
U.S. Pat. No. 4,319,136, issued to Jinkins disclose a data transfer for cranial computerized tomography images that is substantially form-fitting and dome-shaped. First and second groups of elongated depth markers are positioned in front and in back, diametrically across from each other, and each depth marker extends from the peripheral edge of the cap toward the apex of the cap, the markers are positioned parallel to one another and each marker is graduated in length and terminates at its upper end in an enlargement. A plurality of longitudinal or circumferential markers are positioned between the first and second groups of depth markers and also extend from the peripheral edge of the cap toward the apex of the cap.
U.S. Pat. No. 4,971,060, issued to Schneider et al. is directed to an apparatus worn by a patient to provide a geometric reference for medical diagnostic data obtained from the patient has an element rigidly attachable to the patient, this element being connected to other components which emit a known and recognizable signal during the acquisition of medical diagnostic data, those components being used to establish a geometric reference for the data obtained from the patient. In one embodiment, a bite-down plate having a shape corresponding to the dentition of the patient is held in the mouth of the patient, and is connected to a rigid carrier having markings for geometrically referencing a tomographic image.
In another embodiment, the worn element is a rigid ring worn by the patient as a headband, having a number of length-variable indicators, each of which having a scale, and also being connected to a member having a recognizable shape, or having markings, for a reference in tomographic imaging. Both embodiments can be used with other examination equipment, such as devices for obtaining biomagnetic signals, so that the respective data obtained from multiple examination devices can be geometrically correlated.
U.S. Pat. No. 4,341,220, issued to Perry discloses X-ray detectable fiducial markers are associated with a stereotactic surgery frame. The frame is fixed with respect to a patient's anatomy and defines a predetermined three-dimensional coordinate system in which surgical devices may be precisely positioned. A desired target area of the anatomy is detected in a cross-sectional CT scanner depiction of the combined stereotactic frame and patient anatomy. The target's coordinates with respect to the frame are calculated based on three non-collinear fiducial points also located within the cross-section and having known coordinates both with respect to the frame and with respect to the target. In the exemplary embodiment, detachable fiducial point-defining members are associated with a stereotactic surgical frame.
For example, each member may be a plate having a series of parallel grooves or slots which progressively increase in length from one slot to the next. The frame coordinates of the end points of each slot are predetermined and known. Thus three fiducial points with respect to the frame can be determined by simply counting the number of slots or grooves contained within the cross-sectional depiction and thereby determining which end point is within such cross-section.
It is an objective of the present invention to provide a failsafe method of identifying the orientation of a patient in a scanning procedure, especially sidedness, right versus left. It is a still further objective of the invention to provide this method of identification through apparatus adaptable to various types of scanning procedures. Finally, it is an objective of the present invention to provide such identification through inexpensive and disposable fixtures or apparatus that do not interfere with the scanning procedures.
While some of the objectives of the present invention are disclosed in the prior art, none of the inventions found include all of the requirements identified.